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turtle ancestry

...the first modern turtles found in the fossil record, appearing in the Cretaceous Period. The oldest sea turtle (
Santanachelys gaffneyi) is known from the mid-Cretaceous. It is a member of the
Protostegidae, a likely sister group of modern leatherback sea turtles.
S. gaffneyi had a streamlined shell of about 1.5 metres (5 feet) and forelimbs well along the evolutionary path to...